BZOJ 3511 土地划分

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define maxv 50050
#define maxe 500050
#define inf 0x7f7f7f7f7f7f7f7fLL
using namespace std;
long long n,m,vala[maxv],valb[maxv],sum=0,max_flow=0,x,y,a,b,c,s=1,t,nume=1,g[maxv];
long long dis[maxv];
struct edge
{
long long v,f,nxt;
}e[maxe];
queue <long long> q;
void addedge(long long u,long long v,long long f)
{
e[++nume].v=v;e[nume].f=f;
e[nume].nxt=g[u];g[u]=nume;
e[++nume].v=u;e[nume].f=0;
e[nume].nxt=g[v];g[v]=nume;
}
bool bfs()
{
for (long long i=s;i<=t;i++) dis[i]=inf;
dis[s]=0;q.push(s);
while (!q.empty())
{
long long head=q.front();q.pop();
for (long long i=g[head];i;i=e[i].nxt)
{
long long v=e[i].v;
if ((e[i].f>0) && (dis[v]>dis[head]+1))
{
dis[v]=dis[head]+1;
q.push(v);
}
}
}
return dis[t]!=inf;
}
long long dinic(long long x,long long low)
{
if (x==t) return low;
long long ret=0;
for (long long i=g[x];low && i;i=e[i].nxt)
{
long long v=e[i].v;
if ((e[i].f>0) && (dis[v]==dis[x]+1))
{
long long dd=dinic(v,min(low,e[i].f));
ret+=dd;low-=dd;
e[i].f-=dd;e[i^1].f+=dd;
}
}
if (!ret) dis[x]=inf;
return ret;
}
int main()
{
scanf("%lld%lld",&n,&m);t=n;
for (long long i=2;i<=n-1;i++) {scanf("%lld",&vala[i]);sum+=vala[i];vala[i]<<=1;}
for (long long i=2;i<=n-1;i++) {scanf("%lld",&valb[i]);sum+=valb[i];valb[i]<<=1;}
for (long long i=1;i<=m;i++)
{
scanf("%lld%lld%lld%lld%lld",&x,&y,&a,&b,&c);sum+=a+b;
if (x>y) swap(x,y);
if ((x==1) && (y==n))
{
sum-=a+b+c;
continue;
}
if (x==1) vala[y]+=2*a+2*c,sum-=b;
else if (y==n) valb[x]+=2*b+2*c,sum-=a;
else vala[x]+=a,valb[x]+=b,vala[y]+=a,valb[y]+=b;
if ((x!=1) && (y!=n)) addedge(x,y,a+b+2*c),addedge(y,x,a+b+2*c);
}
for (long long i=2;i<=n-1;i++) addedge(s,i,vala[i]),addedge(i,t,valb[i]);
while (bfs())
max_flow+=dinic(s,inf);
printf("%lld\n",sum-max_flow/2);
return 0;
}